wherein R1 is azetidinyl and the like, R2 to R5 is a hydrogen atom or a halogen atom, R6 is C3-8 cycloalkyl and the like, R7 is a hydrogen atom and the like, and R8 is a halogen atom and the like.
The compound represented by Formula (I) has potent inhibitory effects against hepatocyte growth factor receptor (HGFR), and thus is useful as an antitumor agent, an angiogenesis inhibitor, and a tumor metastasis inhibitor (Patent Literature 1). HGFR is known to be overexpressed in a large number of tumor cells (Non Patent Literature 1) and involved in malignant alteration of tumors. Further, HGFR is also expressed in vascular endothelial cells, and is considered to cause the proliferation of tumors by promoting angiogenesis (Non Patent Literature 2).
On the other hand, the compound represented by Formula (II) has anti-angiogenic actions (Patent Literature 2), inhibitory effects (Patent Literatures 3 to 6) against tyrosine kinases which are reported to be involved in malignant alteration of tumors (Non-Patent Literatures 3 to 5), and the like; and is known as a therapeutic agent for various tumors such as thyroid cancer, lung cancer, melanoma, endometrial cancer, gastric cancer and bladder cancer.
In general, antitumor agents are often not effective for all of the patients when they were used individually. Thus, attempts have been made so far to increase the cure rate by combination of plural antitumor agents (Patent Literatures 7 to 9).